Device and method for restructuring heart chamber geometry

ABSTRACT

A geometric reconfiguration assembly for the natural heart having a collar configured for surrounding the natural heart. The collar can include a plurality of bands, such as thin bands of about 0.2 mm in thickness, in a spaced relationship to each other, and a connector bar intersecting the plurality of bands and configured for maintaining the spaced relationship of the bands to each other. The collar may include a plurality of bands, such as from about 2 to about 10 bands, that are positioned parallel to each other. The bands can each be made of a biomedical material, such as polyacetal or a metal, such as titanium or steel.  
     The connector bar of the present invention can be positioned tangential to the plurality of bands, and may have a plurality of grooves configured to receive the thickness of each of the plurality of bands. The grooves also may be beveled to allow for the bands to flex as the heart beats. The connector bar&#39;s inner surface can have an outwardly convex curved configuration, and may even include a cushioned portion that can be made from a polymeric material. A pad may be positioned between the collar and the epicardial surface of the heart that may comprise a low durometer polymer, or either a gel-filled cushion or a fluid-filled cushion.

REFERENCE TO COPENDING APPLICATION

[0001] This is a continuation in part application of U.S. patentapplication Ser. no. 08/581,914, filed Dec. 23, 1997, entitled“Activation Device for the Natural Heart and Method of Doing the Same,”which is a continued prosection application of U.S. patent applicationSer. No. 08/581,914 filed on Jan. 2, 1996.

TECHNICAL FIELD OF THE INVENTION

[0002] The present invention relates to a device and method for treatingcardiomyopathies and/or enlarged hearts and more specifically, a deviceand method for decreasing a heart chamber's wall tension.

BACKGROUND OF THE INVENTION

[0003] The natural heart, and specifically, the cardiac muscle tissue ofthe natural heart (e.g., myocardium) can fail for various reasons to apoint where the natural heart cannot provide sufficient circulation ofblood for a body so that life can be maintained. More specifically, theheart and its chambers can become enlarged for a variety of causesand/or reasons, including viral disease, idiopathic disease, valvulardisease (mitral, aortic and/or both), ischemic disease,

[0004] Chagas' disease and so forth. As the heart and its chambersenlarge, tension of the walls of the heart's chambers increase and thus,the heart must develop more wall tensile stress to generate the neededpressure for pumping blood through the circulatory system. The processof ventricular dilation is generally the result of chronic volumeoverload or specific damage to the myocardium. In a normal heart that isexposed to long-term increased cardiac output requirements, for example,that for an athlete, there is an adaptive process of slight ventriculardilation and muscle myocyte hypertrophy. In this way, the heart mayfully compensate for the increase cardiac output requirements of thebody. With damage to myocardium or chronic volume overload, however,there are increased requirements put on the contracting myocardium tosuch a level that this compensated state is never achieved and the heartcontinues to dilate.

[0005] A problem with an untreated dilated ventricle is that there is asignificant increase in wall tension and/or stress, both during thediastolic filling, and during the systolic contraction. In a normalheart, the adaption of muscle hypertrophy (e.g. thickening) in theventricular dilation maintain a fairly constant wall tension forsystolic constriction. However, in a failing heart, the ongoing dilationis greater than the hypertrophy, and as a result, rising wall tension isrequired for systolic contraction. This is believed to result in furthermuscle damage.

[0006] The increase in wall stress is also true for diastolic filling.Additionally, because of the lack of cardiac output, ventricular fillingpressure tends to rise due to several physiologic mechanisms. Moreover,in diastole, both the diameter and wall pressure increase over normallevels, thus contributing to higher wall stress levels. As a solutionfor the enlarged natural heart, attempts have been made in the past toprovide a treatment to maintain circulation. Prior treatment for heartfailure generally fall into three categories, namely surgicaltreatments; mechanical support systems; or pharmacological.

[0007] One such approach has been to replace the existing natural heartin a patient with an artificial heart or a ventricular assist device. Inusing artificial hearts and/or assist devices, a particular problemstems from the fact that the materials used for the interior lining ofthe chambers of an artificial heart are in direct contact with thecirculating blood, which can enhance undesirable clotting of the blood,build up of calcium, or otherwise inhibit the blood's normal function.Hence, thromboembolism and hemolysis could occur with greater ease.Additionally, the lining of an artificial heart or a ventricular assistdevice can crack, which inhibits performance, even if the crack is at amicroscopic level. Moreover, these devices must be powered by a sourcewhich can be cumbersome and/or external to the body. Drawbacks havelimited use of these devices to applications having too brief a timeperiod to provide a real lasting benefit.

[0008] An alternative procedure is to transplant a heart from anotherhuman or animal into a patient. The transplant procedure requiresremoving an existing organ (i.e., the natural heart) for substitutionwith another organ (i.e., another natural heart) from another human, orpotentially, from an animal. Before replacing an existing organ withanother, the substitute organ must be “matched” to the recipient, whichcan be, at best, difficult and time consuming to accomplish.Furthermore, even if the transplanted organ matches the recipient, arisk exists that the recipient's body will reject the transplanted organand attack it as a foreign object. Moreover, the number of potentialdonor hearts is far less than the number of patients in need of atransplant. Although use of animal hearts would lessen the problem withfewer donors than recipients, there is an enhanced concern withrejection of the animal heart.

[0009] In an effort to use the existing natural heart of a patient,other attempts have been made to reduce wall tension of the heart byremoving a portion of the heart wall, such as a portion of the leftventricle in a partial left ventriculectomy procedure (the Batistaprocedure). A wedge-shaped portion of the ventricular muscle has beenremoved, which extends from the apex to the base of the heart. Byreducing the chamber's volume, and thus its radius, the tension of thechamber's wall is reduced as well. There are, however, several drawbackswith such a procedure. First, a valve (i.e., the mitral valve) may needto be repaired or replaced depending on the amount of cardiac muscletissue to be removed. Second, the procedure is invasive and traumatic tothe patient. As such, blood loss and bleeding can be substantial duringand after the procedure. Moreover, as can be appreciated by thoseskilled in the industry, the procedure is not reversible.

[0010] Another device developed for use with an existing heart forsustaining the circulatory function of a living being and the pumpingaction of the natural heart is an external bypass system, such as acardiopulmonary (heart-lung) machine. Typically, bypass systems of thistype are complex and large, and, as such, are limited to short term usein an operating room during surgery, or to maintaining the circulationof a patient while awaiting receipt of a transplant heart. The size andcomplexity effectively prohibit use of bypass systems as a long termsolution, as they are rarely even portable devices. Furthermore, longterm use of these systems can damage the blood cells and blood borneproducts, resulting in post surgical complications such as bleeding,thromboembolism function, and increased risk of infection.

[0011] Medicines have been used to assist in treating cardiomyopathies.Some inotropic agents can stimulate cardiac work. For example, digoxincan increase the contractibility of the heart, and thereby enhancesemptying of the chambers during systolic pumping. Medicines, such asdiuretics or vasodilators attempt to reduce or decrease the heart'sworkload. For example, indirect vasodilators, such asangiotensin-converting enzyme inhibitors (e.g., enalopril), can helpreduce the tendency of the heart to dilate under the increased diastolicpressure experienced when the contractibility of the heart muscledecreases. Many of these medicines have side effects, such as excessivelowering of blood pressure, which make them undesirable for long termtherapy.

[0012] As can be seen, currently available treatments, procedures,medicines, and devices for treating end-stage cardiomyopathies have anumber of shortcomings that contribute to the complexity of theprocedure or device. The current procedures and therapies can beextremely invasive, only provide a benefit for a brief period of time,or have undesirable side effects which can hamper the heart'seffectiveness. There exists a need in the industry for a device andprocedure that can use the existing heart to provide a practical,long-term therapy to reduce wall tension of the heart, and thus improveits pumping efficiency.

SUMMARY OF THE PRESENT INVENTION

[0013] It is the object of the present invention to provide a device andmethod for treating cardiomyopathies that addresses and overcomes theabove-mentioned problems and shortcomings in the thoracic medicine art.

[0014] It is another object of the present invention to provide a deviceand method for treating cardiomyopathies that minimizes damage to thecoronary circulatory and the endocardium.

[0015] It is still a further another object of the present invention toprovide a device and method for treating cardiomyopathies that maintainsthe stroke volume of the heart.

[0016] Another object of the present invention is to provide a deviceand method for treating cardiomyopathies that supports and maintains thecompetence of the heart valves so that the heart valves can function asintended.

[0017] Still another object of the present invention is to provide adevice and method that increases the pumping effectiveness of the heart.

[0018] Yet another object of the present invention is to provide adevice and method for treating cardiomyopathies on a long term basis.

[0019] It is yet still an object of the present invention to provide adevice and method for treating cardiomyopathies that does not requireremoval of any portion of an existing natural heart.

[0020] Still a further object of the present invention is to provide adevice and method for treating dilated cardiomyopathies that directlyreduce the effective radius of a chamber of a heart in systole as wellas in diastole.

[0021] Additional objects, advantages, and other features of the presentinvention will be set forth and will become apparent to those skilled inthe art upon examination of the following, or may be learned withpractice of the invention.

[0022] To achieve the foregoing, a geometric reconfiguration assemblyfor the natural heart having a collar configured for surrounding thenatural heart. The collar can include a plurality of bands, such as thinbands of about 0.2 mm in thickness, in a spaced relationship to eachother, and a connector bar intersecting the plurality of bands andconfigured for maintaining the spaced relationship of the bands to eachother. The collar may include a plurality of bands, such as from about 2to about 10 bands, that are positioned parallel to each other. The bandscan each be made of a biomedical material, such as polyacetal or ametal, such as titanium or steel.

[0023] The connector bar of the present invention can be positionedtangential to the plurality of bands, and may have a plurality ofgrooves configured to receive the thickness of each of the plurality ofbands. The grooves also may be beveled to allow for the bands to flex asthe heart beats. The connector bar's inner surface can have an outwardlyconvex curved configuration, and may even include a cushioned portionthat can be made from a polymeric material. A pad may be positionedbetween the collar and the epicardial surface of the heart that maycomprise a low durometer polymer, or either a gel-filled cushion or afluid-filled cushion.

[0024] The assembly of the present invention may also comprise a closuredevice for enclosing at least one of the bands in the connector bar.

[0025] In use, the present invention can reduce the wall tension on oneof the chambers of the heart. A yoke or collar is surrounds the heart soas to provide the chamber of the heart as at least two contiguouscommunicating regions, such as sections of truncated ellipsoids, whichhave a lesser minimum radii than the chamber before restructuring. Assuch, the collar displaces at least two portions of the chamber wallinwardly from the unrestricted position.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] While the specification concludes with claims particularlypointing out and distinctly claiming the present invention, it isbelieved the same will be better understood from the followingdescription taken in conjunction with the accompanied drawings in which:

[0027]FIG. 1 partial frontal anterior view of an exemplar natural heart;

[0028]FIG. 2 vertical cross sectional view of an exemplar natural heartand blood vessels leading to and from the natural heart;

[0029]FIG. 3 is a horizontal cross sectional view of an unrestrainedleft ventricle of the natural heart;

[0030]FIG. 4 is a horizontal cross sectional view of a heart restrainedmade in accordance with the present invention;

[0031]FIG. 5 is a perspective view of a device made in accordance withthe present invention;

[0032]FIG. 6 is an enlarged exploded perspective view of a portion ofthe assembly made in accordance with the present invention;

[0033]FIG. 7 is an enlarged perspective view of another portion of theassembly made in accordance with the present invention;

[0034]FIG. 8 is a cross sectional view of a connector of the presentinvention taken along line 8-8 in FIG. 7;

[0035]FIG. 9A is a partial horizontal cross sectional view of anassembly made in accordance with the present invention while the heartis at rest;

[0036]FIG. 9B is a partial horizontal cross sectional view of anassembly made in accordance with the present invention while the heartis contracting:

[0037]FIG. 10 is a perspective view of the assembly made in accordancewith the present invention and positioned in the left ventricle;

[0038]FIG. 11 is an alternative embodiment of the assembly made inaccordance with the present invention;

[0039]FIG. 12 is a cross sectional view of one embodiment of the collarof the present invention taken along line 12-12 in FIG. 11;

[0040]FIG. 13 is another alternative embodiment of the assembly made inaccordance with the present invention;

[0041]FIG. 14 is yet another alternative embodiment of the assembly madein accordance with the invention;

[0042]FIG. 15 is another alternative embodiment of the assembly made inaccordance with the present invention;

[0043]FIG. 16 is a vertical cross sectional view of one embodiment of anauxiliary fastener made in accordance with the present invention;

[0044]FIG. 17 is another vertical cross sectional view of the auxiliaryfastener of FIG. 16 inserted into the assembly;

[0045]FIG. 18 the vertical cross sectional view of the embodiment ofFIG. 16 illustrating the auxiliary connecter; and

[0046]FIG. 19 is a vertical cross sectional view of the auxiliaryfastener of FIG. 16 a period of time after being inserted into position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0047] Referring now to the figures in detail wherein like numeralsindicate the same elements throughout the views, an exemplary naturalheart, generally indicated in FIGS. 1 and 2 as 10, has a lower portioncomprising two chambers, namely a left ventricle 12 and a rightventricle 14, which function primarily to supply the main force thatpropels blood through the circulatory system, namely the pulmonarycirculatory system, which propels blood to and from the lungs, and theperipheral circulatory system, which propels blood through the remainderof the body. a natural heart 10 also includes an upper portion havingtwo chambers, a left atrium 16 and a right atrium 18, which primarilyserve as an entryway to the left and right ventricles 12 and 14,respectively, and assist in moving blood into the left and rightventricles 12 or 14. The interventricular wall 40 of cardiac tissue 32separates the left and right ventricles 12 and 14, and theatrioventricular wall 42 of cardiac tissue 32 separates the lowerventricular region from the upper atrium region.

[0048] Generally, the left and right ventricles 12 and 14, respectively,each has a cavity 13 and 15, respectively, that is in fluidcommunication with cavities 17 and 19, respectively, of the atria (e.g.,16 and 18) through an atrioventricular valve 50 (which are eachillustrated as being in the closed position in FIG. 2). Morespecifically, the left ventricle cavity 13 is in fluid communicationwith the left atrium cavity 17 through the mitral valve 52, while theright ventricle cavity 15 is in fluid communication with the rightatrium cavity 19 through the tricuspid valve 54.

[0049] Generally, the cavities of the ventricles (e.g., 13 and 15) areeach in fluid communication with the circulatory system (i.e., thepulmonary and peripheral circulatory systems) through a semilunar valve44 (which are each illustrated as being in the open position in FIG. 2).More specifically, the left ventricle cavity 13 is in fluidcommunication with the aorta 26 of the peripheral circulatory systemthrough the aortic valve 46, while the right ventricle cavity 15 is influid communication with the pulmonary artery 28 of the pulmonarycirculatory system through the pulmonic valve 48.

[0050] Blood is returned to the heart 10 through the atria (e.g., 16 and18). More specifically, the superior vena cava 22 and inferior vena cava24 are in fluid communication with and deliver blood, as it returns fromthe peripheral circulatory system, to the right atrium 18 and its cavity19. The pulmonary veins 30 are in fluid communication with and deliversblood, as it returns from the pulmonary circulatory system, to the leftatrium 16, and its cavity 17.

[0051] The heart 10 is enclosed in the thoracic cavity within a doublewalled sac commonly referred to as the pericardium. Its inner layer isthe visceral pericardium or epicardium, and its outer layer is theparietal pericardium. The heart 10 is generally made up of, among othermaterials, cardiac muscle or tissue 32, which has an exterior surfacecommonly known as the epicardial surface 34 and an interior surface, orendocardial surface 38, that generally defines the cavities (e.g.,ventricular cavities 13 and 15, respectively, and atrial cavities 17 and19, respectively). Coronary arteries 36 on the epicardial surface 34 ofthe heart 10 provide blood and nourishment (e.g., oxygen) to the heart10 and its cardiac tissue 32.

[0052] By way of a non-limiting example, the present invention will bediscussed in terms of embodiments that are used to primarily assist inthe restructuring or reconfiguring, and/or operation of the leftventricle chamber (e.g., 12) of the natural heart 10. However. it isnoted that the present invention can also be used to assist in therestructuring or reconfiguring, and/or operation of other portions ofthe natural heart 10, such as either atria (16 and/or 18), or the rightventricle chamber (e.g., 14).

[0053] Turning now to FIG. 3, the chambers of the heart 10, includingthe left ventricle chamber 12, is generally shaped as a hollow truncatedellipsoid having, at any circular cross-section perpendicular to itslong axis, a center point “C₁” and a radius “R₁” extending from centerpoint C₁ to the endocardial surface 38. The cardiac tissue 32 of theheart 10 has a thickness “w,” which is generally the distance betweenthe epicardial surface 34 and the endocardial surface 38.

[0054] The assembly 60 of the present invention exemplified in FIGS. 4to 7 preferably is configured and positioned relative to the naturalheart 10 to displace at least two portions of the cardiac tissue 32inwardly (see, e.g., FIG. 4) from the unrestricted position, asexemplified in FIG. 3. By displacing portions of the cardiac tissue 32inwardly, the shape of the chamber (e.g., the left ventricle chamber 12)of the heart 10 is generally restructured or reconfigured from agenerally hollow truncated ellipsoid (see, e.g., FIG. 3) to a chambergenerally shaped as having at least two continuous communicatingportions of truncated ellipsoids (see, e.g., FIG. 4). In generallyreconfiguring or restructuring the heart 10 as such, each of thetruncated ellipsoids has an adjusted radius “R₂,” which is preferablyshorter than radius “R₁.”

[0055] The assembly 60 can be static in that it does not actuate or pumpthe heart 10, but rather, displaces and holds portions of the cardiactissue 32 in a generally predetermined fixed position as the heart 10continues to contract (e.g., beat) and pump blood through its chambersand through the body's circulatory system. Nevertheless, the assembly 60can be configured and constructed to permit torsional deformation as thenatural heart 10 beats.

[0056] The assembly 60 can include a yoke or collar 62, as exemplifiedin FIGS. 5-7, to assist in restraining or restructuring a ventricle,such as the left ventricle chamber 12. Collar 62 can be any desiredshape and preferably surrounds or encircles the heart 10, and preferablyone chamber (e.g., the left ventricle chamber 12) as best exemplified inFIG. 10, so as to restructure or reconfigure the left ventricle chamber12 as having a shape approximating at least two continuous communicatingportions of truncated ellipsoids. Preferably, a portion or region 64 ofthe collar 62 can extend along the longitudinal plane or along thelonger axis of the chamber. Suitable locations on the epicardial surface34 for the region 64 can include the basal portion near theatrioventricular groove 43 (see, e.g., FIG. 1) and apical portion 20 ofthe heart 10, the anterolateral surface of the left ventricle chamber12, or the posteromedial surface of the left ventricle chamber 12.

[0057] The collar 62 may include two or more bands (e.g., 76) configuredfor positioning around the heart 10. Preferably, bands 76 arecircumferentially flat and may be oriented with the surface 78 beingpositioned generally tangent to the epicardial surface 34 of the heart10, and having the smaller dimension, as compared with surface 80.Surface 80 is generally oriented perpendicular to the epicardial surface34. Band 76 should be sized so as to provide for low deformation in thedirection perpendicular to the epicardial surface 34 of the heart 10,but only require a low strain energy for tortial deformation as theheart 1O beats. Band 76 can have a thickness “th” across surface 78 anda width “w” across surface 80, that each varies depending on theselected material and its particular deformation characteristics. Whenmetallic material is used with the present invention, the band 76 canhave a thickness “h” across surface 78 of about 0.2 mm, and can have awidth, “w” across surface 80 from about 5 mm to about 12 mm, and morepreferably, about 7 mm. It should be noted that the particulardimensions of each assembly 60, and of its components (e.g. collar 62and its various portions, bands 76, etc.) will depend, as will bediscussed later, according to particular anatomy, the desiredapplication, and upon the particular size and configuration of theindividual natural heart 10.

[0058] In constructing assembly 60 using bands 76, from about 2 to about10 bands 76 may be used, and preferably about 4 bands 76 are used in thepresent invention. Nevertheless, the number of bands 76 may be selecteddependent upon the property of the material selected for each of thebands 76, as well as the load stress required to appropriatelyrestructure the heart chamber geometry.

[0059] Bands 76 are each preferably made of a light weight, generallyrigid material that has a low bending strain under expected levels ofstress so that the material has sufficient wear resistance in use whilethe heart 10 beats, and maintains its desired shape in use adjacent theheart 10. Illustrative examples of suitable materials which may beemployed as bands 76 include any biocompatible or biomedical materials,such as metals, including titanium or stainless steel, or a suitablepolymer, including polyacetal or an ultra high molecular weightpolyethylene, or a combination of the same.

[0060] The collar 62 may preferably include a connector 82, andpreferably a plurality of connectors 82 spaced along the collar 62, asexemplified best in FIG. 5. The connectors 82 can assist in maintainingthe space relationship of the bands 76 relative to each other, and ofthe assembly 60 to the heart 10. Turning now to FIGS. 6-8, the connector82 preferably has a contact or an inner surface 84, which is configuredfor placement adjacent or against the epicardial surface 34 of thenatural heart 10. The inner surface 84 may be configured so that theepicardial surface 34 may slide along inner surface 84 duringcontraction and expansion of the heart 10, and to minimize damage to theepicardial surface 34, and the coronary arteries (e.g., 36). Preferably,the inner surface 84 is curved convex outwardly in a longitudinal plane(see, e.g., FIGS. 4 and 8) and has a smooth surface, and/or preferablyrounded edges 87 so that collar 62 can be configured to be positionedadjacent or on the epicardial surface 34 whereby intimate contact can beestablished and maintained, even during the contraction or beating ofthe heart 10.

[0061] FIGS. 6-8 illustrate the connectors 82 as each including one ormore grooves 92, which can extend inwardly from an opening 98 in theouter wall 86, and toward the contact or inner surface 84. Each groove92 is preferably sized and configured to receive a band 76 whereby itssurface 78 would be positioned adjacent the base wall 94, and itssurfaces 80 preferably would be positioned adjacent sidewalls 96.

[0062] In an preferred embodiment, groove 92 should be configured toassist in allowing flexion movement of the band 76 as the heart 10 beatsand moves. As best exemplified in FIGS. 6-8, grooves 92 may be taperedinwardly as the grooves 92 proceeds or extends from the outer surface 86inwardly toward the contact surface 84. In addition, grooves 92 may alsobe tapered inwardly as the groove extends from each of the lateralsurfaces 88 inwardly (e.g., upwardly and/or downwardly), as bestillustrated in FIG. 6.

[0063] Connectors 82 are each preferably made of a light weight,generally rigid material that has a low bending strain under expectedlevels of stress so that the material has sufficient wear resistance inuse while the heart 10 beats, and maintains its desired shape in useadjacent the heart 10. Illustrative examples of suitable materials whichmay be employed as connectors 82 may include any biocompatible orbiomedical materials, such as metals, including titanium or stainlesssteel, or a suitable polymer, including polyacetal or an ultra highmolecular weight polyethylene, or a combination of the same.

[0064] Turning back to FIG. 6, a structure 100 can be provided so as toassist in maintaining the bands 76 in the groove 92, in use. Anystructure 100 contemplated for use with assembly 60 should assist inrestricting movement of the band 76 out of the groove 92 through opening98. In one embodiment, the structure 100 may take the form of a plate100 that can be secured or otherwise attached, and preferably releasablysecured, to close off or restrict access through one or more openings98. In addition to a plate-like structure, sutures (not shown) may alsobe threaded through the connector 82 to assist in restricting bands 76movement through opening 98. Structure 100 is preferably made of abiocompatible or biomedical material.

[0065] Turning now to FIGS. 11 and 12, an alternative embodiment of thepresent invention may include a collar or yoke 162 that provides anessentially continuous surface which contacts the epicardium surface 34of the heart 10. In the present embodiment, collar 162 may take the formof a generally continuous yoke-like structure that is essentially rigid.Collar 162 preferably includes a contact or an inner surface 184, whichis configured for placement adjacent or against the epicardial surface34 of the natural heart 10. The inner surface 184 should be configuredso that the epicardial surface 34 may slide along the inner surface 184during contraction and expansion of the natural heart 10, and tominimize damage to the epicardial surface 34 and the coronary arteries(e.g., 36). Preferably, the inner surface 184 is curved convexlyoutwardly in a longitudinal plane and has a smooth surface, and/orpreferably rounded edges 187 so that a collar 162 can be configured tobe positioned adjacent or on the epicardial surface 34 whereby intimatecontact can be established arid maintained, even during the contractionor expansion of the natural heart 10.

[0066] The collar 162 preferably is selected from a generally rigidbiomedical or biocompatable material. Examples of such suitablematerials may include a metal, such as titanium or steel, or a polymer,such as an ultra high molecular weight polyethylene, polyacetal, or apolymer composite material such as carbon fiber-epoxy orfiberglass-epoxy, or a combination of the same. Moreover, the collar 162may be covered, either partially or entirely, with a material thatpromotes tissue ingrowth into the collar 162, such as a soft tissuepolyester fabric sheeting or polyletrafluroethyhere (PTFE).

[0067] In another alternative embodiments, exemplified in FIGS. 13-14,it is contemplated that the collar 162 may include an attachment system163 that allows the collar 162 to be placed around the heart 10, such asinbetween the pulmonary veins 30 near the basal portion of the heart 10so as to reduce the possibility of lateral or medical displacement ofthe assembly 60, or about the lateral atrium or the atrioventrialargroove region. In one embodiment, the collar 162 may include anattachment system 163 that permits the collar 162 to be separated andthen reattached at two or more sites or positions along the collar 162,preferably adjacent or near the region of the collar 162 configured forplacement adjacent or on the basal portion and/or apical portion 20 ofthe natural heart 10. While the attachment system 163 is illustrated asan interlocking pin 163B and receptacle 163A (e.g., a ball andsocket-likejoint), it is contemplated, and as would be appreciated bythose skilled in the art, other devices and assemblies for releaseablysecuring the collar 162 together can be used. Example of such devicesand assemblies for attachment system 163 could include sutures, a screwand bore holes through overlapping portions of the collar 162, clamps, acombination of these devices and assemblies.

[0068] Alternatively, as illustrated in FIG. 14, the collar 162 mayinclude an attachment system 163 at one site along the collar 162,preferably adjacent or at the portion of the collar 162 configured forplacement adjacent on or the basal portion of the heart 10. Thisembodiment of collar 162 preferably would include a portion 167 that caneither include flexible material or a pivotable section 168 to providemovement of the collar 162 so that the attachment assembly 163 can open,and the collar 162 can be slipped around in the heart 10, and/or betweenthe pulmonary veins 30.

[0069] In yet another embodiment illustrated in FIG. 15, the assembly260 may include a collar 262 having a region 264 similar to thestructure of the collar 62, exemplified above in FIGS. 4-8, andconnector portions or regions 268, similar to the structure of thecollar 162, discussed above, and exemplified in FIGS. 12-14.

[0070] To assist the epicardial surface 34 in separating from each ofthe collars 62, 162, or 262 adjacent or at the lateral portions 85 ofinner surface 84 without creating substantial negative pressure, a pad56 can be positioned and/or interposed between the epicardial surface 34and the inner surface 84 of one or more of the connectors 82. Pad 56 canbe, as exemplified in FIGS. 9A and 9B, a fluid-filled or gel-filled pador cushion, which generally will occupy space laterally beyond thecollar 62 and the lateral portions 85 of inner surface 84 while theheart 10 is in as a relaxed state. However, as the heart 10 contractsand the wall shortens (see, e.g., FIG. 9B), generally circumferentially(reducing cavity radius), the epicardial surface 34 will “peel away”from the collar 62 and the lateral portions 85 of inner surface 84 andthus, fluid or gel in the pads 56 can fill this space so that the innersurface 84 and epicardial surface 34 remain in contact and effect focalrestraint whereby the chamber 12 is restructured, as detailed above.

[0071] In one embodiment, the pad 56 is a closed system. Alternatively,it is contemplated that pad 56 can be configured such that fluid and/orgel can be added or removed to enhance functionality of the deviceassembly of the present invention, as desired. For example, one or morelines 58 can be in fluid communication with a chamber in pad 56. Line 58can extend from pad 56 to an injection port 59, which can be positionedsubcutaneous or elsewhere, as desired, for enhanced access. As will beappreciated by those skilled in the art, fluid or gel can be injectedinto the injection port 59 using a standard syringe and needle, or otherdevice, to increase the size of the pad 56 and/or the pressure withinthe pad 56, as desired. Alternatively, fluid or gel can be withdrawn asdesired.

[0072] Alternatively, pad 56 can be as a low durometer polymer such as aplastic or other material (e.g., rubber). In use, as detailed above,the-material accommodates and maintains the contact between the collar62, and more specifically its inner surface 84, and epicardial surface34 and thus, the desired reconfiguration of the heart 10 as the heart 10beats or deforms.

[0073] To assist each of the assembly 60 in remaining fixed in a spatialor spaced relationship to each other and adjacent or on the epicardialsurface 34, as desired, one or more auxiliary connectors 70 is provided.Auxiliary connector 70 can take the form of various mechanicalconnectors used in the industry to attach and position prostheticdevices in the body.

[0074] Auxiliary connector 70 can take the form of a spike shaped objector pin 75 that is configured to penetrate the epicardial surface 34 intothe cardiac tissue 32. Also, auxiliary connector 74 can take the form ofa button 72 and cord 73. One end of the cord 73 can be attached orotherwise secured to the collar 62, and it can extend inwardly into andthrough the cardiac tissue 32. A button 72 can be attached to oradjacent the other end of the cord 86 adjacent the endocardial surface38. Button 72 can be made of any biocompatible material, and ispreferably made of a material that enhances tissue growth around thebutton 72 to minimize the possibility of the formation of blood clots.It is further contemplated that other surgical attachment articles andtechniques can be used in accordance with the present invention, such asscrews, surgical staples and the like, to assist in fastening andsecuring the assembly 60 in position, as desired.

[0075] Furthermore, auxiliary connector 70 can take the form of a peg74, as exemplified in FIGS. 16-19, that can configured to be lockablyreceived in a hole 67 positioned and/or aligned on the assembly 60, andpreferably on the connectors 82 or the collar 162. Peg 74 generallycomprises a generally permanent potion 74A configured preferably to besnugly received in the hole 67, as discussed above. The portion 74A canbe made of any suitable biomedical or biocompatible material. Suitableexamples of materials for portion 74A, can include the same materialsthat can be used with the collar 62, as exemplified above.

[0076] At the end of the portion 74A of the peg 74, a generally rigidabsorbable spike 74B is provided, which preferably is a generallyfustoconicall shaped and tapers inwardly as the spike 74B extends awayfrom the portion 74A. Spike 74B is sufficiently rigid so that it canpierce the tissue and then be inserted into the muscle tissue (e.g., thecardiac tissue 32). The material used for spike 74B should be a materialthat is absorbable by the body tissue over a period of time. Suitablematerials can include a gelatin material, which can be partiallydenatured thermally or chemically to control solubility and theabsorption rate in the tissue (e.g., 32), a polyglycol acid, or othermaterials, as will be appreciated by those skilled in the industry, usedwith absorbable surgical devices or sutures.

[0077] Within the portion 74A and spike 74B is a generally flexibleextension 74C configured, for example, as a strip, coil, tube, or loopwhich preferably may include exposed interstices (mesh), holes, loops orother surface enhancements to promote tissue in growth. Extension 74Ccan be made from a material to enhance tissue integration therein.Suitable examples of materials for use as extension 74C can includepolyester, polypropylene, and other polymers used in as non-dissolubleimplants.

[0078] In accordance with the teachings of the present invention, theassembly 60 should be so configured and positioned adjacent the heart 10whereby the wall tension is reduced in accordance with LaPlace's theoryof a chamber, which is as follows:

[0079] (Tension of wall)=K*(chamber pressure)*(radius of chamber)(wallthickness),

[0080] wherein K is a proportionality constant.

[0081] As an illustrative example of one embodiment in accordance withthe teachings of the present invention, calculations will be performedbased on the following model as exemplified in FIGS. 3 and 5. It isassumed that the long axis of the left ventricle 12 of the heart 10 is100 mm, that the equatorial or short axis of the chamber 12 is 70 mm,that the equatorial wall thickness “w” of the chamber is about 10 mm andthe basal diameter of the heart 10 is 60 mm. An arbitrary slice or planeof the left ventricle 12 will be analyzed to illustrate localdimensional computations for the present invention.

[0082] Furthermore, this model will assume that the inner radius “R₁”(of the slice or plane) of the unrestricted heart 10 (see, e.g., FIG. 3)is about 28.982 mm and that the heart 10 has an outer radius of about38.406 mm. As is known to those skilled in the industry, the width “w”and radius “R₁” can be directly obtained from high-resolution imaging,such as an echocardiogram, or preferably, by computation based on anassumed geometric model. The ratio of the restraint contract pressure ofthe left ventricle 12 of the device 60 to the cavity pressure can varyfrom 1 to about 2. This example will further assume that the allowedratio of the restraint contact pressure of the left ventricle 12 ofdevice 60 to the cavity pressure is to be limited to a maximum of about1.5, which is represented by symbol K in the mathematical formulasbelow. Also, it is desired to achieve an altered radius “R₂” of the leftventricle 12 to 80% of its original radius R₁, and as such:

R₂=0.8*R₁

R₂=0.8*28.982 mm

R₂=23.186 mm

[0083] In order to calculate the radius of curvature “g” of the innersurface 64 of member 62 in the transverse plane, the following formulacan be used:

g=(w+R₂)÷(k−1)

g=(9.424 mm+23.186 mm)÷(1.5−1)

g=(32.61 mm)÷0.5

g=65.22 mm.

[0084] Now that the value of radius of curvature of the inner surface 84“g” has been calculated, the angle “θ” between the line g₁ (joining thecenter of curvature of the member 62 with one margin, in this plane, ofthe contact area between inner surface 84 and the epicardial surface 34)and line g₂ (joining the same center of curvature with the center of theinner surface 84 in the same plane) can be calculated using thefollowing formula:

θ=(π/2)*[R ₂ −R ₁]÷(R ₂ +w+g)

θ=(π/2)*[28.982 mm −23.186 mm]÷(28.982 mm+9.424 mm+65.22 mm)

θ=(π/2)*[5.796 mm]÷(103.636 mm)

θ=0.09063 radius or 5.332 degrees

[0085] Using the formula below, the distance inwardly that the heart 10should be displaced can be calculated so that the desired restructuringcan be achieved. If “e” is the distance that the center of either member62 is to be separated from the absolute center of a remodeled ventriclein this plane, then:

e=[(g+w+R ₂)* cos θ]−g

e=[(65.22 mm+9.424 mm+23.186 mm)* cos 5.332 degrees]−65.22 mm

e=32.21 mm.

[0086] As such, twice e or (2*e) is 64.42 mm, and this is the preferreddistance separating the oppositely disposed inner surfaces 64.

[0087] Based on the calculation, the wall of the heart 10 needs to bedisplaced or moved inwardly about 6.20 mm from the unrestrained positionto achieve the desired restructure or reconfiguration whereby walltension is adjusted, as desired. Also, using the formula 2θg tocalculate the desired contacting width of the inner surface 84, which isabout 11.68 mm in this example.

[0088] To position the assembly 60 into a body (e.g., the thoraciccavity) and around an existing natural heart 10, a high resolutionimage, such as a standard echocardiogram, or other analysis of the heart10 is preferred so that certain anatomical measurements can beelectronically, preferably digitally, recorded and calculated, asdetailed above. While the present application only includes one set ofmathematic calculations to optimize the present invention, it iscontemplated that measurements will need to be taken along several axes,planes, locations or positions along the longer axis of the chamber.Pre-surgical calculations are preferred so that the assembly 60 can beconstructed, as desired, before surgery to minimize surgical time, andpreferably reduce or eliminate use of a heart/lung bypass machine.

[0089] Thoracic surgery may be required to implant assembly 60.Clinically sufficient anesthesia is administered and standard cardiacmonitoring is employed to the patient and then, via a sternal or lateralwall incision, the pericardial sac where the heart 10 is usuallysituated is opened using standard thoracic surgical procedures, whichare known to those skilled in the art.

[0090] Once the thoracic cavity and pericardium is opened, the heart 10must be narrowed or constricted so that the assembly 60 can be placedaround the heart 10. In one embodiment, inflow to the heart 10 may beoccluded. This can be accomplished by placing a tourniquet around eitherthe superior and/or inferior vena cava 22 and 24, respectively, asillustrated respectfully in FIGS. 1 and 2, for a brief period of time(e.g., about 3 to 4 heartbeats) whereby the heart 10 shrinks andempties. Thereafter, the collar 62 may be slipped around the heart 10.The tourniquets can be released from occlusion around the superiorand/or inferior vena cavas 22 and 24, respectively, and the heart 10re-fills with blood.

[0091] While for prolonged reduction of blood pressure by cardiac inflowocclusion, hypothennia techniques may be employed to lower bodytemperature to reduce the side effects that can be caused by reducedblood pressure in the circulatory system.

[0092] If an open heart procedure employed in the present invention,circulation of blood to the natural heart 10 may be bypassed so thepresent invention can be inserted on and/or into the patient. If so,referring back now to FIG. 2, the superior vena cava 22, the inferiorvena cava 24, and aorta 26 are cannulated. The circulatory system isconnected to as a cardiopulmonary bypass machine so that circulation andoxidation of the blood are maintained during the surgical procedure. Byway of example, the procedure discussed in detail will be for insertionof the present invention 60 to restructure or reconfigure the leftventricle chamber 12.

[0093] Turning now to FIGS. 4-7 and 10, assembly 60, which may have beencustomized according to the anatomical measurements and calculations, ispreferably positioned adjacent or against the epicardial surface 34 inpredetermined locations relative to each other and relative to thechamber (e.g., left ventricle chamber 12). Assembly 60 is positionedaround the heart 10 so that portions of the heart 10 are displaced orurged inwardly, as desired.

[0094] Auxiliary connectors 70 can be used to further secure theassembly 60 to the heart 10. Turning now to FIGS. 16-19, peg 74 can beinserted in the hole 67, whereby the spike 74B is piercing theepicardial surface 34 and is being inserted into the tissue (e.g.,cardiac tissue 32). Peg 74 preferably locks into position once inserted(see FIG. 17), to further secure the assembly 60 in place. Over time, itis preferred that spike 74B, which has been inserted into the tissue,dissolve and be absorbed by the surrounding tissue. As the spike 74B isbeing absorbed, extension 74C becomes exposed to the tissue, and tissuethereby insinuates and grows into any exposed interstices, loops, holes,or other surface enhancements to promote tissue ingrowth. The peg 74Bcan thereafter be held in place by the tissue insinuation and growthinto extension 74C, which can assist in maintaining the position ofassembly 60.

[0095] Once the assembly 60 is properly positioned and secured,termination of a cardiopulmonary bypass, if used, is attempted and, ifsuccessful, the thoracotomy is closed.

[0096] Alternatively, once the thoracic cavity and pericardium is open,the collar 162 exemplified in FIGS. 13 and 14, can be placed around theheart 10, either between the pulmonary artery 28 and the superior leftatrial surface or between the aorta and the pulmonary artery 28 and thenacross the posterior dorsal left atrial surface in between the left andright pulmonary veins 30. A portion of the collar 162, preferably theposterior portion, can be placed behind the heart 10. An opening issharply and/or bluntly developed in the leaves of the pericardiumforming the anterolateral margin of the oblique sinus. Then, a hemostatcan be used to place a portion of the collar 162 through the opening.Alternatively, a detachable cord, with one end attached to the portionof the collar 162, can be grasped and used to pull a portion of thecollar 162 through the opening. Such placement of the collar 162 acrossthe epicardial surface 34 of the lateral atrium or atrioventricularjunction should reduce the possibility of adverse medial or lateraldisplacement or movement of the collar 162.

[0097] An alternative method for positioning the present inventionincludes removing the natural heart 10 from the patient, positioning allthe components of the present invention assembly 60, as discussed above,and auto-transplanting the natural heart 10 back into the patient usingstandard cardiectomy and cardiac transplant techniques known in theindustry.

[0098] Having shown and described the preferred embodiments to thepresent invention, further adaptations of the activation device for theliving heart as described herein can be accomplished by appropriatemodifications by one of ordinary skill in the art without departing fromthe scope of the present invention. For example, the present inventioncan be used with any one or even as a plurality of the various chambersof a living heart, and also could be used with different structuralembodiments to restructure he chamber. Several such potentialmodifications have been discussed and others will be apparent to thoseskilled in the art. Accordingly, the scope of the present inventionshould be considered in terms of the following claims and is understoodnot to be limited in the details, structure and operation shown anddescribed in its specification and drawings.

I claim:
 1. A geometric reconfiguration assembly for a natural heart,comprising: a collar configured for surrounding the natural heart andhaving a plurality of bands in a spaced relationship; and a connectorbar intersecting the plurality of bands and configured for maintainingthe spaced relationship of the bands to each other.
 2. The assembly ofclaim 1, wherein the connector bar comprises an inner surface having anoutwardly convex curved configuration.
 3. The assembly of claim 1,wherein each of the plurality of bands are positioned parallel to eachother.
 4. The assembly of claim 1, wherein the assembly comprises fromabout 2 to about 10 bands.
 5. The assembly of claim 1, wherein the bandscomprise a high strength, high modulus polymer.
 6. The assembly of claim1, wherein the bands comprise a metal.
 7. The assembly of claim 1,wherein the connector bar is positioned tangential to the plurality ofbands.
 8. The assembly of claim 1, wherein at least one of the bands hasa thickness of about 0.2 mm.
 9. The assembly of claim 1, wherein each ofthe bands includes a thickness, and the connector bar comprises aplurality of grooves configured to receive the thickness of each of theplurality of bands.
 10. The assembly of claim 9, wherein the connectorbar comprises at least one beveled groove.
 11. The assembly of claim 1,wherein the connector bar comprises a cushioned portion.
 12. Theassembly of claim 1, comprises a closure device for enclosing at leastone of the bands in the connector bar.
 13. The assembly of claim 1,wherein the collar comprises a first restrictor region configured to bepositioned adjacent the anterolateral surface of the heart and a secondrestrictor region configured to be positioned adjacent posteromedialsurface of the heart.
 14. The assembly of claim 11, wherein the cushionportion comprises a polymeric material.
 15. The assembly of claim 1,wherein said assembly comprises a pad provided adjacent the innersurface of the connector bar.
 16. The assembly of claim 15, wherein thepad comprises a low durometer polymer.
 17. The assembly of claim 15,wherein the pad comprises a cushion.
 18. The device of claim 17, whereinthe cushion comprises a gel-filled cushion.
 19. The assembly of claim17, wherein the cushion comprises a fluid-filled cushion.
 20. Ageometric reconfiguration assembly for a natural heart, comprising; acollar for surrounding a portion of the natural heart, said collarhaving a portion configured for placement on the basal portion of thenatural heart in between the left and right pulmonary veins, said collarfurther comprising an attachment assembly configured for releasablyconnecting said collar together.
 21. The assembly of claim 20, whereinthe collar comprises an inner surface having a outwardly convex curveconfiguration.
 22. The assembly of claim 20, wherein the attachmentsystem comprises a pin and receptacle, said pin and receptacle beingreleasably detachable.
 23. A geometric reconfiguration assembly for anatural heart, comprising a collar configured for surrounding a naturalheart, said collar having a first restrictor region for placementadjacent the anterolateral surface of the heart, and a second restrictorregion configured for positioning adjacent the posteromedial surface ofthe heart; the first and second restrictor portions each comprising aplurality of bands in a space relationship and a connector barintersecting the plurality of band and configured for maintaining thespace relationship of the bands to each other.
 24. The assembly of claim23, wherein the collar comprises a first and second connector portionconfigured for placement adjacent the basal portion of the heart and asecond connector portion configured for a position adjacent the apicalportion of the epicardium of the heart.
 25. A method for reducing walltension on one of the chambers of the heart, comprising the steps ofproviding a geometric reconfiguration assembly; and surrounding one ofthe chambers of the heart with a geometric configuration assembly. 26.The method of claim 25, comprising the step of occluding blood inflowinto the heart prior to placement of the assembly around the chamber ofthe heart.